1. Field of the Invention
This invention relates to winch systems for four-wheel drive vehicles and other vehicles and more particularly, to a manual switch for operating direct current (DC) reversible electric winch motors under circumstances where the conventional winch electrical operating system fails. The manual switch is designed to be mounted in or on the winch housing or electrically coupled to the DC electric winch motor in the winch to serve as a backup system for operating the winch. The manual switch of this invention may typically be operated in four ways, including hand-manipulation of a handle-turret assembly or a push-pull knob arrangement mounted on the switch housing, remotely manipulating the handle turret assembly by means of a remote handle connected to the turret by means of wires, and remotely operating the switch by means of solenoids or a rotary actuator mounted on the switch housing and connected to a toggle or other switch by appropriate wiring.
One of the problems inherent in the operation of conventional winch systems and particularly winch systems mounted on four-wheel drive vehicles used for hunting, oil and gas operations and other activities involving operation of the vehicles in remotely located places, is that of moisture, mud, corrosion and other contamination of the various electrical contacts and connections necessary to operate conventional winch systems. Conventional winches are typically operated by four solenoid (SPST) or two solenoid (DPST) electrical arrangements. External connections found in these winch configurations are extremely prone to malfunction due to corrosion, moisture, mud and other contaminants often found in the field where the winches are typically used. The advantage of the manual switch of this invention is that it minimizes the number of external connections necessary in conventional winch systems and provides a sealed housing filled with a contact fluid which prevents foreign matter, air and moisture from degrading the switch contact life. The manual switch of this invention is thus capable of manually operating a winch under circumstances where the conventional winch solenoid or electrical system fails, a common occurrence in the field. The manual switch may be mounted either directly on the winch motor by means of bus bar straps or connected remotely by means of wire leads. Alternatively, the switch can be configured in the winch frame itself, as desired. Furthermore, the manual switch of this invention can be configured in a manual-only mode by implementing a hand-operated, handle-turret assembly or it can be remotely operated by means of a pair of U-control wires connected to a bracket mounted on a rotatable turret attached to the switch housing, to distance the operator from the wire rope or cable in the winch in case the cable fails. Similar remote electrical operation can be effected by means of a pair of solenoids or a rotary actuator mounted on the winch housing and connected to the internal movable contact bars to effect the desired forward and reverse operation of the direct current reversible winch motor.
2. Description of the Prior Art
Various types of electric winches and hoists are known in the art. U.S. Pat. No. 1,945,712, dated Feb. 6, 1934, to R. J. Wadd, details a "Hoist" wherein the major elements of the hoist, which include the motor, wire rope, drum and reduction gearing between the motor and drum, are so closely and advantageously organized as to provide for a smooth and easy application of power of the motor to the drum in a balanced manner to prolong the life of the hoist and insure long term satisfactory and efficient operation. U.S. Pat. No. 2,274,280, dated Feb. 24, 1942, to K. W. Stinson details a hoist having a mechanical contrivence located between the control lever and the controller switch, such that in event that the control cords attached to the lever are too quickly operated in the act of reversing rotation of the motor shaft, the control mechanism will be temporarily locked for a period of time sufficient to permit the motor to come to a standstill. U.S. Pat. No. 2,301,678, dated Nov. 10, 1942, to C. Brongersma, details a "Controller Actuator" which embodies novel centrifugal weight and stop arrangements, such that the weight will be jammed against the stop to prevent full throw of the controller from one extreme position to the other except when the controller has shifted slowly. An "Electric Winch Apparatus" is detailed in U.S. Pat. No. 4,556,199, dated Dec. 3, 1985, to Ryan F. Dansie, et al. The device has an alternating current motor and direct current operable clutch and brake coils, together with a control circuit for energizing the apparatus. The control circuit includes alternating current switching of DC current flows, operator control of both reeling in and unreeling drum functions and selected use of separate brake release and brake hold-off coils, with a combination of full-wave and half-wave energizing currents. U.S. Pat. No. 4,789,135, dated Dec. 6, 1988, to H. Watanabe, details an "Operating Device For Electric Hoist". The device has a DC motor for raising and lowering an object and includes a low speed adjusting setting unit and a high speed adjusting setting unit provided in a control box. The operating device further includes a two-step push button switch for the raising operation, for switching over the low speed adjusting setting unit and the high speed adjusting setting unit to connect either of the units to a speed-change control circuit by pushing the two-step push button switch to either a first or a second step position. A second two-step push button switch energizes the lowering operation for switching over the low speed adjusting setting and the high speed adjusting setting units. U.S. Pat. No. 5,167,400, dated Dec. 1, 1992, to G. Anthoine, details a "Control Device For Lifting Winches, In Particular for Drilling Rigs". The control device includes a control circuit that facilitates controlled excitation of an electric motor. A manipulator on a control panel controls the control circuit by establishing, according to its position, a given speed request instruction. An indexing circuit for controlling the control circuit is adapted on the basis of predetermined end-of-travel positions and in accordance with a given law relating the speed to the difference in height between a given end of travel position and the actual height of the time in question, to establish a given speed request instruction. A comparator passes to the control circuit only the speed request instruction that it receives representing the lowest speed.
It is an object of this invention to provide a new and improved manual switch for direct current, reversible electric winches, which manual switch is designed to mount on or in the winch housing of the electric winch or electrically connect to the reversible DC motor in the electric winch to operate the DC electric motor in the forward and reverse directions exclusive of the conventional operating switches and electrical components of the winch.
Another object of this invention is to provide a new and improved manual winch switch which is characterized by a sealed switch housing mounted on or in the winch housing of an electric winch and connected to the DC reversible winch motor for operating the winch motor in the event of failure of the conventional electrical winch-operating system.
Yet another object of this invention is to provide a manual switch for mounting on or in a conventional DC electric winch housing and electrically connected to the reversible DC electric motor in the winch for manually operating the winch by hand-manipulation of a turret handle or push-pull knobs attached to the switch housing or remotely operating the switch by manipulation of a control handle connected to the switch housing by means of wires or by energizing a rotary actuator or solenoids mounted in the switch housing.
Another object of this invention is to provide a new and improved sealed, substantially fail-safe manual switch for operating a winch in the event of failure of the conventional winch electrical system, which manual switch includes a switch housing containing spring-loaded contact bars as well as fixed contacts insulated from the housing and from each other and located in a pool of contact fluid sealed in the housing, wherein the fixed contacts in the housing are connected to the reversible DC electric winch motor and the spring-loaded contact bars within the housing are selectively manipulated by hand-operation of a turret assembly or push-pull knobs mounted on the switch housing or by a remote handle connected to the fixed housing by means of wires or by means of a rotary actuator or a pair of solenoids mounted on the housing and connected to the contact bars and operated by a toggle switch, to operate the reversible DC electric winch motor when the conventional winch electrical system fails.